Question

/** converts 'WinMain' to the traditional 'main' entrypoint **/
#define PRO_MAIN(argc, argv)\
    int __main (int, LPWSTR*, HINSTANCE, int);\
    int WINAPI WinMain (HINSTANCE __hInstance, HINSTANCE __hPrevInstance, \
                       LPSTR __szCmdLine, int __nCmdShow)\
    {\
        int nArgs;\
        LPWSTR* szArgvW = CommandLineToArgvW (GetCommandLineW(), &nArgs);\
        assert (szArgvW != NULL);\
        return __main (nArgs, szArgvW, __hInstance, __nCmdShow);\
    }\
    \
    int __main (int __argc, LPWSTR* __argv, HINSTANCE __hInstance, int __nCmdShow)

Now, when I use this code here:

PRO_MAIN(argc, argv)
{
  ...
}

I get the error:

error: conflicting types for '__main'
note: previous declaration of '__main' was here

What’s the problem?

Answer 1

You have broken the rules: double-underscores are reserved for implementation! (Among other things.)

You simply cannot use __main, main__, _Main, etc. You should pick something else.

I would recommend you make this work:

int main(int argc, char* argv[])
{
    // main like normal
}

// defines WinMain, eventually makes call to main()
PRO_MAIN;

Which has the added advantage that for non-Windows applications, PRO_MAIN can simply expand to nothing, and the program still compiles with the standard main function. This is what I do.